diff --git a/lib/prawn.rb b/lib/prawn.rb
index 47f0297a0..df1a255fb 100644
--- a/lib/prawn.rb
+++ b/lib/prawn.rb
@@ -37,7 +37,7 @@ module Prawn
   # @return [Boolean]
   attr_accessor :debug
 
-  module_function :debug, :debug=
+  module_function :debug, :debug= # rubocop:disable Style/AccessModifierDeclarations
 
   module_function
 
diff --git a/prawn.gemspec b/prawn.gemspec
index 9ae7c30c7..c4ca6e29d 100644
--- a/prawn.gemspec
+++ b/prawn.gemspec
@@ -53,6 +53,6 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency('pdf-inspector', '>= 1.2.1', '< 2.0.a')
   spec.add_development_dependency('pdf-reader', '~> 1.4', '>= 1.4.1')
-  spec.add_development_dependency('prawn-dev', '~> 0.4.0')
+  spec.add_development_dependency('prawn-dev', '~> 0.5.0')
   spec.add_development_dependency('prawn-manual_builder', '~> 0.4.0')
 end
diff --git a/spec/prawn/document/security_spec.rb b/spec/prawn/document/security_spec.rb
index f12b808bd..682d75be8 100644
--- a/spec/prawn/document/security_spec.rb
+++ b/spec/prawn/document/security_spec.rb
@@ -82,7 +82,7 @@ def doc_with_permissions(permissions)
     let(:pdf) do
       Prawn::Document.new do |pdf|
         class << pdf
-          public :owner_password_hash, :user_password_hash, :user_encryption_key
+          public :owner_password_hash, :user_password_hash, :user_encryption_key # rubocop:disable Style/AccessModifierDeclarations
         end
         pdf.encrypt_document(
           user_password: 'foo',